1. Field of the Invention
This invention relates to photographic film processing apparatus and, more particularly, it concerns an improved processor which prevent leakage of any residue processing fluid from the interior of the processor.
2. Description of the Prior Art
As a result of recent developments in the motion picture art, motion picture systems have been devised in which exposure, processing and projection operations are carried out on a photographic film strip contained at all times in a multipurpose cassette. Such a system has been disclosed in several U.S. patents, assigned in common with the present invention. In these cassettes a supply of light sensitive film can be exposed in a camera adapted to receive the cassette. Processing or developing of the exposed film, to provide the conventional series of positive transparent image frames, is achieved by merely placing the cassette in a player or processing and viewing apparatus capable of activating a processor contained in the cassette. During the processing mode, the exposed film is rewound and a coating or layer of processing fluid from the processor is deposited along the length of the film. After processing in this manner, the player apparatus is operated as a projector to advance the film incrementally, frame by frame, past a light source. As a result, the scene to which the film was exposed is capable of being reproduced on a screen.
While the advance in the motion picture art represented by such a system is apparent and needs no elaboration herein, it is critical to satisfactory performance of the system that the processing fluid not leak. Failure to prevent leakage will damage the cassette interior, including the film strip. Thus, undesirable blemishes may be observed in the film's images during projection thereof. It follows, therefore, that prevention of processing fluid leakage is a significant point of attention in overall system development.
The current state of the art with respect to preventing such leakage is represented by the disclosure of U.S. Pat. No. 3,785,725 issued Jan. 15, 1974 to John F. Batter, Jr., Paul B. Mason, Joseph A. Stella, Paul W. Thomas, Jr. and Joseph H. Wright; and U.S. Pat. No. 3,806,245 issued Apr. 23, 1974, to Edwin H. Land and John Batter, Jr. which patents are commonly assigned with the present application.
In the disclosures of these patents, a pad of sponge-like material is used to prevent leakage. Such pad is wettable and swellable by the cassette contained processing fluid, and is positioned to engage any residue fluid trying to escape through a passage in the processor, which passage permits withdrawal of the tear-tab during the tear-tab release. Thus, any residue processing fluid contacting the sponge causes expansion of the sponge pad to seal the passage against escape of the processing fluid.
While the foregoing approach successfully operates to seal the residue processing fluid against escape there are, however, potential for operational problems. One is the fact that if tiny sponge particles exist they can fall into the fluid and adversely affect the processing fluid coating of the film. Further drawbacks with the foregoing approach are that the sponge pad is relatively costly and must be carefully manufactured and assembled into the cassette. Moreover, some approaches required more than a single pad for leakage prevention.
As will later be explained, the illustrated embodiment employs capillary grooves to control the residue fluid; however, it is known to provide minute V-shaped energy directors along the length of certain margins of the processing well cover to facilitate ultrasonically welding the cover to the cassette wall formations to thereby retain the processor pod and released processing fluid. Such energy directors, incidentally, result in the formation of grooves. However, the energy-directors and grooves are not situated to control and inhibit the residual fluid through the passage and are not dimensioned to trap the processing fluid through capillary adhesion.